Preventing fog on a medical device viewport

ABSTRACT

Provided are methods of immunizing a viewport of a medical device against fogging before or during a medical procedure, and related apparatuses and devices. The methods comprise applying plasma to the viewport prior to use, thereby rendering a surface of the viewport highly hydrophilic. The methods eliminate or at least significantly reduce blur due to fogging.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No.15/757,659 filed on 6 Mar. 2018, which is a U.S. National Stage of PCTInternational Application No. PCT/IL2016/050990 filed on 7 Sep. 2016,which claims priority to U.S. Provisional Application No. 62/215,061filed on 7 Sep. 2015. The disclosure of each of the foregoingapplications is incorporated herein, in its entirety, by this reference.

FIELD OF THE INVENTION

The invention, in some embodiments, relates to the field of medicaldevices having a viewport such as endoscopes, and more particularly, butnot exclusively, to methods and devices for immunizing medical devicesagainst accumulation of fog on the viewport during a medical procedure.

BACKGROUND OF THE INVENTION

Endoscopes are widely used in medical procedures, particularly inminimally invasive surgical procedures. Here, an “endoscope” is intendedto include any scope that has a distal end configured to be insertedinto a patient's body, and a proximal end configured to remain outsidethe patient's body during the procedure. Typically, the distal endcomprises a viewport such as a lens or a window or a bare end of anoptical fiber or even a mirror (such as a dentist mirror for example).Through the viewport, the scope enables collecting an image of thesurrounding of the viewport, e.g. using a light-sensitive device such asa CCD. The viewport may be aimed to collect light from in front of thedevice (namely from a region coinciding with the longitudinal axis ofthe device), or the viewport may be slanted in an angle relative to thelongitudinal axis, or may be facing perpendicular to the longitudinalaxis of the device (as is demonstrated for example in colonoscopies).The proximal end typically includes or is connected to a handle to beheld by a medical practitioner, possibly including user interfacecomponents such as switches, navigating sticks, touch screens and touchpads.

Endoscopes include a vast range of scopes, for example bronchoscopes,colonoscopes, cystoscopes and laparoscopes. A laparoscope—as a specificexample—comprises a rigid or relatively rigid rod or shaft having aviewport, possibly including an objective lens, at the distal end, andan eyepiece and/or an integrated visual display at the proximal end. Thescope may also be connected to a remote visual display device or a videocamera to record surgical procedures.

In a laparoscopic procedure, the patient's abdominal or pelvic cavity isaccessed through one or two or more relatively small incisions(typically between about 3 mm and about 15 mm) and a laparoscope may beinserted through one of the incisions to allow the practitioner a viewof the internal organs to be operated on. The abdomen is typicallyinflated with a gas through the use of an insufflator—carbon dioxide isusually used for insufflation—to distend the abdominal space byelevating the abdominal wall above the internal organs and therebycreate a sufficient working and viewing space for the surgeon.

The local environment within a patient's abdominal space is generallyhumid and warm compared to the laparoscope which is being inserted.Consequently, the viewport of the laparoscope tends to blur, e.g. due tofog, that is to say due to condensation of vapor on the viewport, or,for example, due to accumulation of droplets, e.g. blood dropletsoriginating from surgical activity during the procedure.

Some existing techniques used to clean the viewport of endoscopesrequire retreating the endoscope from the patient's body, rinsing theviewport or wiping it (e.g. with a cloth) and possibly drying the distalend and worming it, to reduce and slow down blur formation afterintroducing the endoscope back in the patient's body. Other existingtechniques include rinsing the viewport inside the patient's body. U.S.Pat. No. 8,047,215 discloses a laparoscopic lens cleaner which issuitable for maintaining the lens of a laparoscope in a clean, drycondition during a laparoscopic surgical procedure. An embodiment of thelaparoscopic lens cleaner includes an elongated cleaner sheath having asheath interior, a fluid conduit provided in the cleaner sheath, a fluiddischarge nozzle provided in the sheath interior and communicating withthe fluid conduit, a gas conduit provided in the cleaner sheath and agas discharge nozzle provided in the sheath interior and communicatingwith the gas conduit. US patent application 20150005582 discloses amethod of defogging and cleaning a laparoscope. The method includes:inserting a laparoscope into a sheath; inserting the laparoscope andsheath into a body cavity; providing gas to a plurality of gas lumenswithin a wall of the sheath such that the gas flows through the gaslumens and over a lens of the laparoscope to defog the lens while thelaparoscope is in the body cavity; and providing a fluid comprising asurface-active agent to a fluid lumen within the wall of the sheath suchthat the fluid flows through the fluid lumen and over the lens to cleanthe lens while the laparoscope is in the body cavity.

SUMMARY OF THE INVENTION

Aspects of the invention, in some embodiments thereof, relate todefogging—namely decreasing or preventing blur and fog—on a viewport ofa medical device. More specifically, aspects of the invention, in someembodiments thereof, relate to methods and devices for immunizing themedical device against accumulation of fog on the viewport during amedical procedure.

As discussed above there are existing techniques for maintaining aviewport of a medical device clear during a medical procedure in whichthe medical device is used inside a patient's body. Such techniquesinvolve active cleaning of the viewport, either by removing the medicaldevice from the patient's body and cleaning the viewport with a cloth orby rinsing, or by rinsing the viewport (and possibly drying it usingflow of gas) inside the patient's body, and are therefore less thanoptimal. Interruption of the medical procedure for cleaning results inlengthening the time of the procedure and may further cause variouscomplications resulting from mind distraction of the medicalpractitioner or generally due to carrying out activity steps that arenot medically required. Extracting the medical device from the patient'sbody for carrying out the cleaning is even worse, as such removal andthen re-introduction of the device into the body may be a source of yetadditional complications.

One reason that condensation of vapor on a viewport might cause blur, isthat the condensed liquid—e.g. water, possibly mixed with bodyfluids—condenses into droplets which distort the light rays passingthrough the droplets, thereby ruining the optical quality of theviewport. In other words, each droplet might function as a lens,focusing or diverging or generally distorting the light rays passingtherethrough in uncontrolled directions. The total effect of themultitude of droplets on the viewport is thus generating an opticallyrough surface, thereby preventing obtaining a sharp image from lightpassing the viewport (or reflecting therefrom).

There is thus provided, according to an aspect of some embodiments, amethod of immunizing a viewport against fogging during use. According tosome embodiments the view port may be a view port of a medical devicesuch as an endoscope and the process of immunization may be providedprior to using the medical device in a medical procedure. The methodcomprises applying a plasma-generating electromagnetic field in a closedchamber that houses the viewport, in close vicinity to the viewport. Theplasma treatment of the viewport is configured to increasehydrophilicity so as to achieve complete wetting of the viewport bywater. Complete wetting is achieved by increasing the surface tension ofthe treated surface of the viewport to above the surface tension ofwater, namely above 0.072 N/m. Preferably, the surface tension of theviewport surface is elevated to above 0.08 N/m and even above 0.1 N/mfor a limited time period following the plasma treatment as explainedabove. When the surface tension of the treated surface of the viewportis greater than the surface tension of water, water does not accumulatein droplets on the surface but rather wet the surface, having a contactangle of substantially 0 degrees. Thus, the method eliminates or atleast significantly reduces blur due to fogging because condensation ofmoisture on the hydrophilic surface of the viewport results in a thinand even layer of fluid, thereby maintaining the optical quality of theviewport or at least limiting the degradation of the optical quality.Variations of fluid thickness on the viewport is reduced by the plasmatreatment, and thereby variability in optical lengths associated withpassing of light through the condensed fluid on the viewport is reducedas well.

The effects of plasma treatment on hydrophilicity of a treated surfaceare often temporary, so that hydrophilicity of a treated surface tendsto decrease over time after the exposure to plasma ends. The method thusfurther comprises using the viewport (or the device in which theviewport is installed)—namely exposing the viewport to moisture—soonafter applying the plasma. “Soon after” means within 24 hours,preferably within 6 hours and even more preferably using the viewportwithin less than an hour after applying the plasma thereto.

It is noted that according to the teachings herein, plasma is generatedin a Dielectric Barrier Discharge (DBD) mode, to ensure uniformity ofthe plasma generating electric field in the vicinity of the view port,and hence to ensure the quality of the plasma treatment. The “quality”of the plasma treatment herein denotes the level of hydrophilicityattained, and the duration of time during which the electric field isactivated to obtain that hydrophilicity. In other words, a high-qualityplasma treatment achieves a relatively high level of hydrophilicity(e.g. obtaining a surface tension above that of water namely above 0.072N/M on the treated surface) within a relatively short duration (e.g. of5 minutes, or 1 minute or as short as 10 seconds or even as short as 5seconds of activated electric field).

Plasma generation in a DBD mode may be effected, for example, byelectrically isolating one of the electrodes used for applying thefield. Such isolation may be realized by a dielectric layer thatisolates the electrode from the gas in the region where plasma isgenerated; or a DBD mode may be effected, for example, by a dielectriclayer that interrupts a line-of-sight between two electrodes betweenwhich the plasma-generating field is applied. For example, according tosome embodiments, a dentist's mirror may be treated according to theteachings herein by placing the distal end of the device including themirror with, e.g. a segment of the metallic handle, in a close chamber,electrically connecting a cathode to the metallic handle and applying aRF high voltage to an anode which is electrically isolated from thegaseous medium around the mirror. According to other exemplaryembodiments, a view port made of a dielectric material such as glass orplastic and having no metallic parts in a vicinity thereof may betreated according to the teachings herein by being positioned in betweentwo exposed electrodes used to apply the plasma-generating electricfield, so that the view port itself is used as a dielectric barrier byinterrupting the line of sight between the electrodes.

Generating plasma in a DBD mode as described herein allows positioningthe electrodes at a relatively short distance from one another and at ashort distance from the treated surface, and applying a relativelystrong field while maintaining the field relatively uniform in closevicinity to the treated surface of the view port, thereby providing ahigh-quality plasma treatment to the treated surface (“relatively” hereis used as compared to generating plasma not in a DBD mode).

According to an aspect of some embodiments there is further provided anapparatus for preparing an endoscope for an endoscopy procedure. Theapparatus comprises a protecting shroud dimensioned to receive therein adistal end of the endoscope, the distal end comprising a viewportconfigured to enable collecting an image of the surrounding of theviewport there through. The apparatus further comprises a plasmagenerating field applicator, electrically associated with an electricpower source and having a slot configured to receive therein the distalend of the endoscope shrouded within the protecting shroud. The plasmagenerating field applicator is configured to apply inside the slot anelectric field suitable for plasma generation proximal the viewport. Theprotecting shroud is detachable from the distal end of the endoscope andfrom the plasma generating field applicator.

According to some embodiments the protecting shroud comprises at leastone electrode and at least one shroud electric contact configured toelectrically contact a corresponding applicator electric contact in theplasma generating field applicator when the protecting shroud isinserted into the slot. The at least one electrode is thereby configuredto apply a plasma generating field within the protecting shroud uponreceiving the electric power from the plasma generating fieldapplicator.

According to an aspect of some embodiments there is provided an methodof preparing an endoscope for an endoscopy procedure, comprisingproviding a protecting shroud dimensioned to receive therein a distalend of the endoscope, the distal end comprising a viewport configured toallow collecting an image of the surrounding of the viewport therethrough. The method further comprises providing a plasma generatingfield applicator, wherein the protecting shroud is detachable from thedistal end and from the plasma generating field applicator. The plasmagenerating field applicator is electrically associated with an electricpower source and has a slot configured to receive therein the distal endof the endoscope shrouded within the protecting shroud. The plasmagenerating field applicator is configured to apply electric powersuitable for plasma generation within the protecting shroud. The methodfurther comprises positioning the distal end of the endoscope shroudedwithin the protecting shroud in the slot of the plasma generating fieldapplicator, and activating the power source to generate plasma withinthe protecting shroud, thereby plasma-treating the viewport of thedistal end. According to some embodiments the method further comprisespreventing, by the protecting shroud, contamination of the plasmagenerating field applicator with fluids dispersed on the distal end.

According to an aspect of some embodiments there is further provided amethod of preparing an endoscope for an endoscopy procedure, theendoscope comprising a distal end comprising a view port. The view portis made of a dielectric material and is proximal to a metallic segmentat the distal end of the endoscope. The method comprises placing thedistal end of the endoscope in a plasma chamber that has at least ananode and a cathode wherein the cathode electrically contacts themetallic segment. A line-of-sight between the anode and the cathode isinterrupted by a dielectric barrier, and the method further comprisesapplying a plasma-generating electromagnetic field between the anode andthe cathode, thereby generating plasma in a DBD mode in a vicinity ofthe view port. According to some embodiments, the electric barrierelectrically isolates the anode from gas in the vicinity of the viewport.

According to some embodiments the viewport is transparent such as aviewport of a laparoscope. According to some embodiments the viewport isa mirror such as in a dentist's mirror. According to some embodimentsthe viewport is made of glass or quartz or plastic.

According to some embodiments, preparing an endoscope for an endoscopyprocedure according to any of the procedures described herein, mayinclude wetting the view port following the plasma treatment.Preferably, such wetting should be carried out prior to the endoscopyprocedure or during the endoscopy procedure, prior to inserting theendoscope to the body of the patient. Such wetting may be carried out bydipping the view port in a liquid, preferably a polar liquid such aswater or an aqueous solution. According to some embodiments such wettingmay be carried out by wiping the view port with an article which iswetted by a desired liquid, e.g. by a wet cloth or a sponge or the like.Additionally or alternatively such wetting of the view port may becarried out by dispensing a controlled and accurate amount ofliquid—e.g. an accurately measured droplet—on the view port. Accordingto some such embodiments the amount of liquid may be calculated to beproportionate to the surface area of the view port, assuming a uniformliquid thickness. The resulting uniform liquid thickness may be smallerthan about 100 microns (100 um) and even smaller than about 20 um, forexample about 20 um or about 10 um, or about 5 um or about 1 um or about0.5 um or about 0.2 um or about 0.1 um or even smaller than about 0.1um. According to some embodiments the liquid may be water, or saline oran aqueous solution having a reduced surface tension (in air) such as asurfactant or a detergent. Such liquid may also comprise bio-compatiblecomponents or agents, e.g. hyaluronic acid.

Thus, according to some embodiments, a user may plasma-treat a view portof an endoscope according to the teachings herein, and soon after theplasma treatment, wet the view port as described above. Followingwetting the view port, the user may proceed to insert the endoscopedistal end to the patient's body in the course of the medical procedurebeing carried out.

This invention separately provides an apparatus which can be used forplasma treating a view port of a medical instrument such as anendoscope, for activating an external surface of the view port so as toobtain a surface tension of the external surface which is higher thanthe surface tension of water.

This invention separately provides a method of preparing a medicalinstrument having a view port, such as an endoscope, for a medicalprocedure, by plasma treating the view port for rendering the view porthighly hydrophilic, thereby preventing blur due to fogging on the viewport during use.

This invention separately provides a method of preparing a medicalinstrument for a medical procedure soon before the medical procedure oreven during the medical procedure. The invention also provides anapparatus configured to provide plasma treatment to a medical instrumentsuch as an endoscope soon before the medical procedure or even duringthe medical procedure in a clean and sterile environment.

Certain embodiments of the present invention may include some, all, ornone of the above advantages. Further advantages may be readily apparentto those skilled in the art from the figures, descriptions, and claimsincluded herein. Aspects and embodiments of the invention are furtherdescribed in the specification hereinbelow and in the appended claims.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention pertains. In case of conflict, thepatent specification, including definitions, governs. As used herein,the indefinite articles “a” and “an” mean “at least one” or “one ormore” unless the context clearly dictates otherwise.

BRIEF DESCRIPTION OF THE FIGURES

Some embodiments of the invention are described herein with reference tothe accompanying figures. The description, together with the figures,makes apparent to a person having ordinary skill in the art how someembodiments may be practiced. The figures are for the purpose ofillustrative description and no attempt is made to show structuraldetails of an embodiment in more detail than is necessary for afundamental understanding of the invention. For the sake of clarity,some objects depicted in the figures are not to scale.

In the Figures:

FIG. 1A schematically depicts an embodiment of an apparatus forpreparing a medical device to a medical procedure, according to theteachings herein;

FIG. 1B schematically depicts a distal end of an endoscope, the distalend comprising a viewport suitable to be plasma-treated by the apparatusof FIG. 1A;

FIG. 1C schematically depicts a sterility screen of the apparatus ofFIG. 1A, comprising a sterility sleeve for covering the plasmaapplicator of the apparatus of FIG. 1A, the sterility sleeve beingrolled prior to use;

FIG. 1D schematically depicts the sterility screen of FIG. 1C, whereinthe sterility sleeve is partially unrolled to cover the plasmaapplicator;

FIG. 1E schematically depicts the sterility screen of FIG. 1C, whereinthe sterility sleeve is unrolled thereby covering the plasma applicator;

FIG. 2 schematically depicts an embodiment of a protecting shroud of anapparatus for preparing a medical device to a medical procedureaccording to the teachings herein, the protecting shroud shrouding anendoscope to-be plasma-treated;

FIG. 3A schematically depicts a protecting shroud positioned inside aslot of a plasma applicator of the apparatus;

FIG. 3B schematically depicts a detail of the protecting shroud of FIG.3A;

FIG. 3C schematically depicts another embodiments of a protecting shroudand a generating field applicator for preparing a medical device to amedical procedure according to the teachings herein, and

FIG. 4 schematically depicts yet another embodiment of a protectingshroud of an apparatus for preparing a medical device to a medicalprocedure according to the teachings herein.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

The principles, uses and implementations of the teachings herein may bebetter understood with reference to the accompanying description andfigures. Upon perusal of the description and figures present herein, oneskilled in the art is able to implement the teachings herein withoutundue effort or experimentation. In the figures, like reference numeralsrefer to like parts throughout.

FIG. 1A schematically depicts an apparatus 100, according to an aspectof some embodiments, for preparing a medical device 200 such as anendoscope, to a medical procedure. Medical device 200 comprises a distalend 210, schematically depicted also in FIG. 1B. Distal end 210comprises a viewport 220 configured to enable collecting an image of thesurroundings of the viewport. Viewport 220 may be in some embodiments atransparent sheet such as a window or a lens, of material such as glassor quartz, or plastic such as Perspex, thereby allowing light from theoutside of the medical device 200 to be collected in the inside ofmedical device 200, e.g. by a light sensitive device (not shown here)such as a camera. According to some embodiments viewport 220 may be amirror, reflecting light (rather than transferring light there through)towards a light collecting apparatus (not shown here) or a lightsensitive device. Viewport 220 comprises a surface 222 which during amedical procedure may be exposed to moisture. Consequently, if nottreated, e.g. immunized against fogging, surface 222 may thereby becomecovered with fog, such fog being the result of accumulation of dropletson the surface 222, e.g. (but not limited to) due to condensation ofvapor.

Apparatus 100 comprises a protecting shroud 110 dimensioned to receivetherein distal end 210 of the medical device 200. Apparatus 100 furthercomprises an operating unit 120 and a plasma applicator 130 (alsoreferred to herein as a plasma generating field applicator) connected tothe operating unit 120. Plasma applicator 130 comprises a slot 132configured to receive therein distal end 210 of medical device 200,whereas distal end 210 is shrouded within protecting shroud 110. Inother words, for use, distal end 210 of medical device 200 is insertedinto protecting shroud 110, and protecting shroud 110, with distal end210 being shrouded therein, is inserted into slot 132. According to someembodiments protecting shroud 110 is inserted into slot 132, and thendistal end 210 is inserted and advanced into protecting shroud 110.

According to some embodiments apparatus 100 further comprises asterility screen 140 having an opening 142. For use, protecting shroud110 is inserted into slot 132 through opening 142 of sterility screen140, as is further detailed and explained herein below. According tosome embodiments protecting shroud 110 is a dispensable, disposable orreplaceable part, being configured to be used during a single medicalprocedure carried out on a single patient. According to someembodiments, the protecting shroud functions as a sterility barrierbetween the endoscope which may be exposed to body fluids of thepatient, and the plasma applicator, which may or may not be maintainedsterile during use and after use. According to some embodimentssterility screen 140 facilitates maintaining plasma applicator 130 clearof body fluids originating in the endoscope during use and after use.According to some embodiments sterility screen 140 facilitatesmaintaining the endoscope sterile against contamination that mayoriginate in plasma applicator 130.

According to some embodiments sterility screen 140 is attached to asterility sleeve 144, as depicted schematically in FIGS. 1C, 1D and 1E,the sterility sleeve extending between the sterility screen and a sleevedistal end 146. According to some embodiments sterility sleeve 144 maybe soft like a sock. Prior to use, sterility sleeve 144 may be folded,as schematically depicted in FIG. 1C. For use, sterility sleeve 144 maybe unfolded to encompass, envelop and cover plasma applicator 130 or aportion thereof by inserting the plasma applicator into the sterilitysleeve through the sleeve distal end 146. During use, sterility sleeve144 may be disposed around plasma applicator 130 so as to envelop andcover plasma applicator 130, so that insertion of protecting shroud 110through opening 142 and into slot 132, and/or insertion of endoscope 200into protecting shroud 110, may not contaminate plasma applicator 130.According to some embodiments the sterility sleeve may be substantiallyrigid, having a shape of e.g. a tube, being configured to house theprotecting shroud therein. According to some embodiments sterilitysleeve 144 comprises a double-sided sticky pad (not shown here) in abottom portion thereof configured to stick on one side to plasmaapplicator 130 and to stick on another side to a desk or a table oranother working platform, thereby attaching and stabilizing the plasmaapplicator to the working platform and facilitating inserting andextracting protecting shroud 110 (or endoscope 200) from plasmaapplicator 130. According to some embodiments, sterility screen 140together with sterility sleeve 144, are attached to protecting shroud110, so that insertion of protecting shroud 110 to the slot 132 andencapsulating plasma applicator 130 with sterility sleeve 144 areperformed substantially together.

Plasma applicator 130 is electrically associated with an electric powersource (not shown here). The power source may be optionally situated inoperating unit 120. Plasma applicator 130 is further configured, whendistal end 210, shrouded within protecting shroud 110, is positionedinside slot 132, and upon activation of the power source, to applyinside protecting shroud 110 inside slot 132 an electric field suitablefor plasma generation proximal viewport 222.

According to some embodiments plasma applicator 130 may be fluidlyassociated with a gas pump and additionally or alternatively with a gasreservoir (neither one is shown here). The gas pump and the gasreservoir may be used to controllably evacuate, or to controllably flushwith a preferred gas, respectively, a vicinity of the distal end of theendoscope, to facilitate plasma ignition, as is further detailed andexplained below. According to some embodiments, a preferred gas may beargon or nitrogen. According to some embodiments, a gas pressuresuitable for plasma ignition after evacuation may be below 0.1 Atm.According to some embodiments, the vicinity of the distal end of theendoscope may be pumped and evacuated and then flushed with a desiredgas. According to some embodiments, the gas pump and/or the gasreservoir, as the case may be, may be optionally situated in theoperating unit 120.

Operating unit 120 is configured to enable a user of apparatus 100 tooperate and control the apparatus. Operating unit 120 may thus comprisecommand switches and controllers, such as physical or virtual switches,buttons and controllers. The control unit may further compriseindicators for providing a user with required data and information foroperating the apparatus, such as indication LEDs, displays and possiblyan operating software for providing a user with operating and commandscreens to allow a user operate and command the apparatus.

FIG. 2 schematically depicts in a cross-sectional view, an embodiment ofa protecting shroud 310 according to an aspect of some embodiments.Protecting shroud 310 is particularly suitable for use with an endoscope380, depicted schematically inside protecting shroud 310 in dashedlines. Endoscope 380 comprises a distal end 382 and an electricallyconducting surface—e.g. a metallic surface 384—at distal end 382,proximal a viewport 390. Viewport 390 further comprises an externalsurface 392, which may be subject to plasma treatment as describedherein.

Protecting shroud 310 comprises a hollow cylinder 312 extending betweena proximal opening 314 and a cylinder distal end 316. Protecting shroud310 further comprises a vacuum seal 320 comprising three O-rings 320 a,320 b and 320 c, respectively. Vacuum seal 320 is adapted to fit anexternal dimension (e.g. an external diameter) of endoscope 380 so as toallow insertion of endoscope 380 into protecting shroud 310 using aslight force, e.g. by hand, as is known in the art. Accordingly, vacuumseal 320 is configured to hold a pressure difference (or gasconcentration difference) between an inside 322 of protecting shroud 310and an outside 324 of protecting shroud 310 when endoscope 380 ispositioned inside protecting shroud 310. Vacuum seal 320 may also assistin mechanically stabilizing endoscope 380 inside protecting shroud 310,thereby assisting in preventing gas leakage between the inside 322 andthe outside 324, and also assisting in plasma generation proximalviewport 390, as is further explained below.

Protecting shroud 310 further comprises a cathode 330 arranged on hollowcylinder 312 and configured to establish an electrical feedthroughbetween the outside 324 of protecting shroud 310 and the inside 322thereof. Cathode 330 is flexible and electrically exposed on the inside322 of protecting shroud 310 and on the outside thereof, therebyallowing insertion of endoscope 380 into protecting shroud 310 whileforming an electric contact between cathode 330 and metallic surface384. Protecting shroud 310 further comprises an anode 340 arrangedproximal to cylinder distal end 316. Anode 340 may be shaped as ametallic block having for example a circular smooth surface 342 facingthe inside 322. According to some embodiments the surface 342 may becurved. According to some embodiments (not shown here) anode 340 may beshaped as a pointed tip pointing towards the inside 322. According tosome embodiments anode 340 may be shaped as a ring. Anode 340 is mountedon a disk 344 made of a dielectric material, so that disk 344 forms adielectric barrier between anode 340 and cathode 330 and metallicsurface 384 of the endoscope (which is on a same potential as thecathode). In other words, disk 344 is configured to ensure plasmageneration in a Dielectric Barrier Discharge (DBD) mode of operation, byinterrupting a line-of-sight between the anode 340 and cathode 330 andmetallic surface 384 of the endoscope, thereby forming said dielectricbarrier. In a DBD mode, plasma may be generated more uniformly over theavailable space in the vicinity of the view port, whereas arcing orother types of specific and narrow electric transportation trajectoriesbetween the anode and the cathode are prevented.

It is noted that the thickness of the dielectric barrier has a strongeffect on the uniformity of the plasma generating electric field in thevicinity of the view port, and hence on the quality of the plasmatreatment. The “quality” of the plasma treatment herein denotes thelevel of hydrophilicity attained, and the duration of time during whichthe electric filed is activated to obtain that hydrophilicity. In otherwords, a high-quality plasma treatment achieves a relatively high levelof hydrophilicity (e.g. obtaining a surface tension above that of waternamely above 0.072 N/M on the treated surface) within a relatively shortduration (e.g. of 5 minutes, or 1 minute or as short as 10 second oreven as short as 5 second of activated electric field). The thickness ofthe dielectric barrier should generally be as low as possible tofacilitate plasma ignition, yet it should be large enough to preventbreakdown and arcing. Exemplary thickness of a dielectric material suchas PET or polycarbonate in embodiments described herein may be in therange of about 0.3 mm to about 3 mm for RF electric field at frequenciesin the MHz range (e.g. about 2 MHz).

According to some embodiments anode 340 is configured to displaceflexibly relative to hollow cylinder 312, to facilitate a reliableelectrical contact between anode 340 and a feeding contactor as isexplained further below. According to some embodiments disc 344 may besupported by springs 346 relative to the cylinder 312.

In operation a plasma generating electric power is supplied betweenanode 340 and cathode 330 and consequently a plasma generating electricfield in a DBD mode is generated between anode 340 and metallic surface384 which is in contact with cathode 330. The plasma generating electricfield generates plasma in the space between anode 340 and cathode 330and particularly in the vicinity of viewport 390 and adjacent externalsurface 392.

FIG. 3A schematically depicts a portion of an embodiment of a plasmaapplicator 348 suitable for use with protecting shroud 310 a (protectingshroud 310 a is slightly different from protecting shroud 310 of FIG. 2,as is detailed below). Plasma applicator 348 comprises a slot 350configured for receiving therein protecting shroud 310 a (whereinendoscope 380 is shrouded within protecting shroud 310 a). Plasmaapplicator 348 further comprises a cathode contactor 352 configured tocontact cathode 330 when protecting shroud 310 a is inside slot 350. Anelectric conductor 354 such as an electric wire, electrically associatedwith cathode contactor 352, may be used to supply electric powergenerated by a power source (not shown here) to cathode contactor 352and to cathode 330. Plasma applicator 348 further comprises an anodecontactor 356 configured to contact anode 340 when protecting shroud 310a is inside slot 350. An electric conductor 358 such as an electricwire, electrically associated with anode contactor 356 may be used tosupply electric power generated by the power source to anode 340. Anodecontactor 356 may be supported flexibly, e.g. by a spring 360, tofacilitate a reliable electric contact between anode contactor 356 andanode 340 when protecting shroud 310 a is inserted to the slot.

It is noted that characteristics of the electric field that couldgenerate plasma in a gas may depend strongly on characteristics of thegas itself, in addition to the electrodes geometry involved (such asshape and configuration of electrodes used for the application of theelectric field, distance between the electrodes etc.). Generally, thehigher the pressure of the gas, the higher the electric field should beto ignite plasma in the gas. Also, some gases ignite at lower fieldsthan others. For example, plasma may be ignited in helium gas atatmospheric pressure and using an RF field (in a frequency between 1 MHzand 15 MHz) of about 7 KV over a distance of 1 cm between electrodes,and at a voltage of about 200V if the gas is at a pressure of 0.8 KPa.With a similar configuration of electrodes and at similar fieldfrequencies, plasma may be ignited in air at a voltage of about 20 KV inatmospheric pressure and at a voltage of about 800V in 0.8 KPa.

Thus, according to some embodiments, plasma applicator 348 is configuredto stream gas from a gas reservoir (not shown here) to slot 350, or topump air from slot 350, to generate a low-pressure atmosphere in thespace between the electrodes 330 and 340, to facilitate plasma ignition.Thus, according to some embodiments, plasma applicator 348 is connectedto a hose 364 fluidly associating a gas reservoir (not shown here)containing a gas suitable for plasma generation therein such as heliumor argon or nitrogen, with slot 350. A valve 366 controlled by a controlunit (not shown here) operable by a user, may be used to schedule andregulate the flow of gas into slot 350. During operation, according tosome embodiments, after introducing protecting shroud 310 a withendoscope 380 therein into slot 350, valve 366 may be opened to allowgas flow into the slot. Protecting shroud 310 a may be penetrable to gasflow through openings 368 between hollow cylinder 312 and disc 344,enabling the gas to flow into protecting shroud 310 a and towardsviewport 390. Excess of gas flowing into slot 350 may freely escapethrough the gap in slot 350 between protecting shroud 310 a and plasmaapplicator 348 (the gap being not sealed). Following a suitable timeperiod of gas flow (e.g. 5 seconds or 10 second or 30 second or even 1minute) the electric power source may be activated to supply power toanode 340 and cathode 330 to generate a plasma generating electric fieldnear viewport 390. According to some embodiments the gas reservoir maybe portable and suitable for a single time use.

According to some embodiments, hose 364 may be used to pump gas (air)from protecting shroud 310 a and particularly from the space nearviewport 390, to facilitate plasma ignition. Air may be sucked from thevicinity of viewport 390 through openings 368 towards slot 350 and intohose 364. A vacuum seal 370 enables generating vacuum near viewport 390by withholding a pressure difference between a region near cylinder end316 and a region near opening 314 of protecting shroud 310 a. Accordingto some embodiments air may be pumped through hose 364 by a vacuum pump(not shown here), fluidly associated with hose 364. According to someembodiments hose 364 may be fluidly associated to a pumped container(not shown) which is continuously pumped, e.g. by a small vacuum pump.Fluid association is provided through hose 364, the hose being inconstant fluid communication with the container thereby being alsocontinuously pumped. Opening valve 366 may result in pumping slot 350and particularly the space near viewport 390 by the vacuum pump or bythe pumped container, depending on the particularities of theembodiment. The volume of the pumped region in fluidly connected partsof slot 350 and of protecting shroud 310 a may be, according to someembodiments, smaller than 10 cc, and a pumped container and hose of e.g.about 1000 cc (1 liter) may suffice to establish a suitable vacuum levelbetween e.g. about 0.1 atm and about 0.01 atm within less than about 5or less than about 10 seconds, which may be sufficient for plasmaexcitation for about 30 seconds or even about 1 minute to satisfactorilyplasma-treat external surface 392.

According to some embodiments, depicted in detailed in FIG. 3B,protecting shroud 310 a further comprises a sterility filter 372positioned in openings 368 for maintaining a sterility barrier betweenprotecting shroud 310 a and plasma applicator 348. By maintaining asterility barrier it is meant that microbial organisms may not penetratesterility filter 372, wherein microbial organisms may include any formof prokaryotic cells or eukaryotic cells, including fungi and bacteria.The sterility filter is disposed according to some embodiments acrosscylinder end 316 in openings 368, so that gas flowing from plasmaapplicator 348 into protecting shroud 310 a enters the protecting shroudsterile, and/or gas flowing from the inside 322 of protecting shroud 310a into plasma applicator 348 enters the plasma applicator sterile. Thus,the sterility filter 372 prevents transfer of contamination from theplasma applicator (e.g. from surroundings of slot 350) onto endoscope380, and/or prevents transfer of contamination from endoscope 380 ontothe plasma applicator. Additionally or alternatively, a sterility filtermay be positioned in the plasma applicator, or for example in hose 364.

FIG. 3C schematically depicts a plasma applicator 448 and acorresponding protecting shroud 410 according to some exemplaryembodiments. Plasma applicator 448 is different from plasma applicator348 in comprising an applicator gas port 402 fluidly associated withhose 364, and protecting shroud 410 comprises a shroud gas port 404configured to fluidly connect to the applicator gas port 402. Fluidconnectivity between the inside 322 of the protecting shroud and theoutside 324 of protecting shroud 410—e.g. the space of slot 450 of theplasma applicator—is prevented by a vacuum seal 408, e.g. an O-ring.Thus, when the protecting shroud 410 is inserted into the plasmaapplicator 448, the shroud gas port 404 fluidly connects to theapplicator gas port 402 thereby establishing fluid connectivity of hose364 to the inside 322 of the protecting shroud. Consequently, aplasma-ignition facilitating gas (such as helium or argon) may be drivendirectly into the protecting shroud through hose 364, and additionallyor alternatively, gas, and particularly air, may be pumped from theprotecting shroud through hose 364. Fluid connectivity between the slot450 and the inside 322 of the protecting shroud is thus prevented. Asterility filter 472 is positioned inside shroud gas port 404, formaintaining a sterility barrier between the inside 322 of protectingshroud 410 and plasma applicator 448. As explained above regradingsterility filter 372 in FIG. 3B, gas flowing from plasma applicator 448into the inside 322 of protecting shroud 410 enters the protectingshroud sterile, and/or gas flowing from the inside 322 of protectingshroud 410 into plasma applicator 448 enters the plasma applicatorsterile. Thus, the sterility filter 472 prevents transfer ofcontamination from the plasma applicator (e.g. from surroundings of slot450) onto endoscope 380, and/or prevents transfer of contamination fromendoscope 380 onto the plasma applicator.

Protecting shroud 410 is further different form protecting shroud 310 inhaving a ring anode 440 shaped as a ring on an external circumference ofhollow cylinder 312 near distal cylinder end 316 (instead of anode 340in protecting shroud 310). Hence hollow cylinder 312, being made of adielectric material, functions as a dielectric barrier 444 between anode440 and cathode 330 and metallic surface 384 of the endoscope, so thatplasma is generated in protecting shroud 410 in a DBD mode of operationas described above regarding protecting shroud 310. According to someembodiments protecting shroud 410 comprises a stopper 442 inside hollowcylinder 412. Stopper 442 is configured to limit advancement ofendoscope 380 into protecting shroud 410, so that a pre-determined,desired gap is established between anode 440 and metallic surface 384 ofthe endoscope, thereby ensuring plasma generation at a known field (thefield being determined by the voltage supplied between the cathode andthe anode and the said gap). Stopper 442 may further be employed as adielectric barrier on the line of sight between the anode and thecathode, thereby assisting in focusing plasma towards the view port 390.

When protecting shroud 410 is inserted into a slot 450 of plasmaapplicator 448, an anode contactor 456 of plasma applicator 448 contactsring anode 440. Anode contactor 456 is electrically associated with anelectric conductor 458 which is configured to connect to a power supply(not shown here) to enable providing to ring anode 440 a plasmagenerating electric field as described above. It is noted that cathode330 is of protecting shroud 410 is electrically associated with cathodecontactor 352 when protecting shroud 410 is inserted into a slot 450 asdescribed above. Thus, upon activation, a suitably connected powersupply may provide a plasma generating electric field (in a DBD mode)between ring anode 440 and the metallic surface 384 of endoscope 380 togenerated plasma in the vicinity of view port 390.

FIG. 4 schematically depicts a protecting shroud 510 according to anaspect of some embodiments. Protecting shroud 510 is configured toenable facilitated plasma ignition, without pumping the space around theendoscope as described in the embodiments above nor without streaminggas into that space. In other words, protecting shroud enables providingplasma treatment to a view port of an endoscope according to theteachings herein, using a plasma applicator that is not connectedneither to a gas reservoir nor to a gas pump. Accordingly, theprotecting shroud does not have a gas port such as gas port 402, and isnot connected to a hose such as hose 364.

Protecting shroud 510 comprises hollow cylinder 312 extending betweenopening 314 and cylinder end 316. Protecting shroud 510 is differentfrom protecting shroud 310 in that hollow cylinder 312 is blind andsealed near cylinder end 316, thereby substantially preventingpermeation or penetration of gas molecules through cylinder end 316.Protecting shroud 510 is further different from protecting shroud 310 inhaving a leakage seal 530 inside hollow cylinder 312, and a hermeticscreen 518 in hollow cylinder 312 situated between leakage seal 530 andcylinder end 316. Hermetic screen 518 is configured to be impermeable togas molecules, thereby defining a closed space 520, closed betweenhermetic screen 518 and cylinder end 316. Closed space 520 insideprotecting shroud 510 is thus airtight, namely maintained sealed fromthe outside 324 of protecting shroud 510. Closed space 520 contains agas suitable for plasma ignition, e.g. Argon, at a gas pressure of about1 atmosphere, so that there is, at most, only minor pressure gradientsover the hermetic screen.

Hermetic screen 518 is breakable, being thereby configured to break(tear down) upon insertion of an endoscope such as endoscope 380 intoprotecting shroud 510. According to some embodiments, protecting shroud510 further comprises one or more tearing needles 522 attached flexiblyto hollow cylinder 312 near hermetic screen 518 outside of closed space520. Tearing needles 522 are configured to lean flexibly towardshermetic screen 518 and to tear the hermetic screen when pushed by anobject inserted into the protecting shroud. Thus, for use, the endoscopemay be inserted into protecting shroud 510 and affecting tearing down ofhermetic screen 518 by pushing tearing needles 522 towards hermeticscreen 518. The endoscope may be further advanced until the viewport isbetween cathode 330 and anode 340. It is noted that during insertion,the endoscope is first advanced through leakage seal 530, then hermeticscreen 518 is broken and then the endoscope is further advanced to bepositioned in place. Once hermetic screen 518 is broken, the gas insidespace 520 is prevented from freely flowing towards opening 324 by asealing formed between leakage seal 530 and the endoscope. Duringfurther advancement of the endoscope into the protecting shroud, thefree volume of space 520 for the gas reduces, yet pressure build up inthe region of closed space 520 is prevented, due to gas escape under apressure difference across leakage seal 530. As a result, when endoscope380 is fully inserted into protecting shroud 510, closed space 520 andparticularly the space proximal the viewport, between anode 340 andcathode 330, comprises substantially the gas that was contained in thespace 520 before the tear-up of hermetic screen 518, at approximatelyatmospheric pressure, thereby facilitating plasma ignition therein.According to some embodiments hermetic screen 518 may be made of Mylaror metalized Mylar or Kapton or metalized Kapton and the like.

There is thus provided according to an aspect of the invention anapparatus (100 in FIG. 1A) for preparing an endoscope ((200 in FIG. 1,380 in FIGS. 2, 3A and 3C) for an endoscopy procedure. The apparatuscomprises a protecting shroud (110 in FIG. 1A, 310, 310 a in FIGS. 2 and3A, 410 in FIG. 3C, 510 in FIG. 4) dimensioned to receive therein adistal end (210, 382) of the endoscope. The distal end comprises a viewport (220, 390) configured to enable collecting an image of thesurrounding of the view port there through.

The apparatus further comprises a plasma generating field applicator(130, 348, 448), electrically associated with an electric power source.The plasma generating field applicator has a slot (132, 350, 450)configured to receive therein the distal end of the endoscope shroudedwithin the protecting shroud. The plasma generating field applicator isconfigured to apply electric power suitable for plasma generation withinthe protecting shroud. The protecting shroud is detachable from thedistal end of the endoscope and from the plasma generating fieldapplicator.

According to some embodiments the view port of the endoscope may betransparent or may be a mirror.

According to some embodiments the apparatus further comprises asterility sleeve (144) extending between a first end (146) and a secondend (140), configured to encapsulate the plasma generating fieldapplicator, having on the first end a first opening configured to enableinserting the plasma generating field applicator into the sterilitysleeve, and on second end a second opening (142) configured to enableinserting the endoscope into the plasma generating field applicator.According to some embodiments the sterility sleeve is soft and accordingto some embodiments the sterility sleeve is rigid. The sterility sleeveis detached from the plasma generating field applicator. According tosome embodiments the sterility sleeve is attached to the protectingshroud, and according to some embodiments the sterility sleeve isdetached from the protecting shroud.

According to some embodiments the protecting shroud comprises at leastone electrode (340, 440) and a first shroud electric contact (340, 440)electrically connected to the electrode. The first shroud electriccontact is configured to electrically contact a corresponding firstapplicator electric contact (356, 456) in the plasma generating fieldapplicator when the protecting shroud is inserted into the slot (350,450). The at least one electrode is thereby configured to apply a plasmagenerating field inside (322) the protecting shroud upon receiving theelectric power from the plasma generating field applicator.

According to some embodiments the protecting shroud further comprises asecond shroud electric contact (330), configured to contact theendoscope when the distal end of the endoscope is received within theprotecting shroud. The second shroud electric contact is configured toelectrically contact a second applicator electric contact (352) when theprotecting shroud is inserted into the slot (350, 450).

According to some embodiments the protecting shroud comprises a hollow,substantially rigid tube (312, 412) extending between an opening (314)configured to receive the distal end of the endoscope, and a distal end(316) of the protecting shroud. According to some embodiments the hollowtube is a hollow cylinder (312, 412).

According to some embodiments the protecting shroud further comprises aseal (320, 530) positioned between the opening and the distal end alongan inner circumference of the hollow tube, being dimensioned to encirclethe endoscope (380), being thereby configured to sealingly contact theendoscope when the endoscope is received inside the hollow tube.According to some embodiments the seal comprises an O-ring.

According to some embodiments the plasma generating field applicator(348, 448) is connected to a hose (364). The hose is controllablyfluidly connected to the slot (350, 450). According to some embodimentsthe plasma generating field applicator (348, 448) comprises a controlledvalve (366), controllably fluidly connecting the hose (364) with theslot (350, 450). According to some embodiments the plasma generatingfield applicator (348) comprises an applicator gas port (402) fluidlyconnected with the hose, and the protecting shroud (410) comprises ashroud gas port (404). The shroud gas port is configured to sealinglyconnect with the applicator gas port for fluidly connecting the hosewith an inside (322) of the protecting shroud. The sealed connectionbetween the shroud gas port and the applicator gas port prevents, e.g.by seal 408, flow communication between the inside (322) of theprotecting shroud (fluidly associated with hose 364) and the slot (450),when the protecting shroud is inserted into the slot.

According to some embodiments the protecting shroud (510) comprises aseal (530) inside the hollow tube (312) configured to sealingly contactthe endoscope when the distal end of the endoscope is inserted into thehollow tube. The protecting shroud (510) further comprises a hermeticscreen (518) spanning across the hollow tube and configured to therebydefine a closed and sealed space (520) between the hermetic screen andthe distal end (316) of the hollow tube. According to some embodimentsthe protecting shroud further comprises a terrier (522) positionedinside the hollow tube between the seal (530) and the hermetic screen(518) being configured to tear down the hermetic seal upon insertion ofthe endoscope into the hollow tube.

According to an aspect of some embodiments there is provided a method ofpreparing an endoscope for an endoscopy procedure. The method comprisesproviding a protecting shroud (110, 310, 310 a, 410, 510) dimensioned toreceive therein a distal end (210, 382) of the endoscope, the distal endcomprising a view port (220, 390) configured to allow collecting animage of the surrounding of the view port there through. The methodfurther comprises providing a plasma generating field applicator (130,348, 448) electrically associated with an electric power source. Theplasma generating field applicator has a slot (132, 350, 450) configuredto receive therein the distal end of the endoscope shrouded within theprotecting shroud. The plasma generating field applicator is configuredto apply electric power suitable for plasma generation within theprotecting shroud (e.g. by the electrodes 330, 340 and 440). Theprotecting shroud is detachable from the plasma generating fieldapplicator and from the distal end of the endoscope. The method furthercomprises positioning the distal end of the endoscope shrouded withinthe protecting shroud in the slot of the plasma generating fieldapplicator, and activating the power source to generate plasma withinthe protecting shroud, thereby plasma-treating the view port at thedistal end of the endoscope.

According to some embodiments, the method further comprises preventing,by the protecting shroud, contamination of the plasma generating fieldapplicator with fluids dispersed on the distal end. According to someembodiments, the plasma generation field applicator comprises a hose(364) and the method further comprises controllably (by closing andopening valve 366) flowing a gas into an inside (322) of the protectingshroud, or pumping the inside of the protecting shroud via the hose.

According to an aspect of some embodiments there is further provided amethod of preparing an endoscope (380) for an endoscopy procedure, theendoscope comprising a distal end (382) comprising a view port (390).The view port is made of a dielectric material and is proximal to ametallic segment (384) at the distal end of the endoscope. The methodcomprises placing the distal end of the endoscope in a closed plasmachamber (e.g. protecting shrouds 310, 310 a, 410 or 510, wherein theinsertion of the endoscope seals the inside 322 of the protectingshrouds, thereby defining a closed plasma chamber therein). The closedplasma chamber has at least an anode (340, 440) and a cathode (330)wherein the cathode electrically contacts the metallic segment. Aline-of-sight between the anode and the cathode is interrupted by adielectric barrier (344, 444), and the method further comprises applyinga plasma-generating electromagnetic field between the anode and thecathode, thereby generating plasma in a DBD mode in a vicinity (322) ofthe view port. According to some embodiments, the electric barrier (444)electrically isolates the anode (440) from gas in the vicinity (322) ofthe view port. According to some embodiments of the method, the viewport is transparent or alternatively is a mirror. According to someembodiments of the method the view port is made of glass or quartz orplastic.

It is appreciated that certain features of the invention, which are, forclarity, described in the context of separate embodiments, may also beprovided in combination in a single embodiment. Conversely, variousfeatures of the invention, which are, for brevity, described in thecontext of a single embodiment, may also be provided separately or inany suitable sub-combination or as suitable in any other describedembodiment of the invention. No feature described in the context of anembodiment is to be considered an essential feature of that embodiment,unless explicitly specified as such.

Although steps of methods according to some embodiments may be describedin a specific sequence, methods of the invention may comprise some orall of the described steps carried out in a different order. A method ofthe invention may comprise all of the steps described or only a few ofthe described steps. No particular step in a disclosed method is to beconsidered an essential step of that method, unless explicitly specifiedas such.

Although the invention is described in conjunction with specificembodiments thereof, it is evident that numerous alternatives,modifications and variations that are apparent to those skilled in theart may exist. Accordingly, the invention embraces all suchalternatives, modifications and variations that fall within the scope ofthe appended claims. It is to be understood that the invention is notnecessarily limited in its application to the details of constructionand the arrangement of the components and/or methods set forth herein.Other embodiments may be practiced, and an embodiment may be carried outin various ways.

The phraseology and terminology employed herein are for descriptivepurpose and should not be regarded as limiting. Citation oridentification of any reference in this application shall not beconstrued as an admission that such reference is available as prior artto the invention. Section headings are used herein to ease understandingof the specification and should not be construed as necessarilylimiting.

The invention claimed is:
 1. A method of preparing an endoscope for anendoscopy procedure, the endoscope including a distal end comprising aview port configured to enable collecting an image of the surrounding ofthe view port there through, the method comprising: providing a plasmachamber including an opening and a seal dimensioned and configured toreceive the distal end of the endoscope in the opening, the plasmachamber further including at least one electrode electrically associatedwith a power source and configured to apply in the plasma chamber aplasma generating electromagnetic field; inserting the distal end of theendoscope to the plasma chamber through the opening so that the seal andthe distal end together seal the opening; and supplying electromagneticpower from the power source to the at least one electrode, therebyapplying the plasma generating electromagnetic field and generatingplasma in the vicinity of the view port.
 2. The method of claim 1,further comprising controllably flowing a gas into an inside of theplasma chamber or pumping the inside of the plasma chamber.
 3. Themethod of claim 1 wherein plasma is generated in the plasma chamber inthe dielectric barrier discharge mode of operation.
 4. The method ofclaim 1 wherein the plasma chamber includes: a protecting shroud havingsaid opening and seal, dimensioned to receive therein the distal end ofthe endoscope; and a plasma generating field applicator, having a slotconfigured to receive therein the distal end of the endoscope shroudedwithin the protecting shroud; wherein the protecting shroud isdetachable from the plasma generating field applicator and the methodfurther comprises preventing, by the protecting shroud, contamination ofthe distal end by contaminants from the plasma generating fieldapplicator.
 5. The method of claim 1, further comprising wetting theview port with a polar liquid following said step of generating plasma.6. The method of claim 5 wherein said wetting is carried out by dippingthe view port in the liquid or by wiping the view port with an articlewetted by the liquid or by dispensing a measured amount of the liquid onthe view port.
 7. The method of claim 5 wherein the liquid is water oran aqueous solution.
 8. The method of claim 7 wherein the aqueoussolution has a surface tension lower than the surface tension of water.